This invention relates to slide calculators, and in particular, to a calculator for determining factors relating to metabolic requirements and parenteral feeding dosage requirements in humans.
Intravenous nutrition is used in a large variety of medical situations, and it is therefore necessary to determine the dosage, or amount, of solution which should be given to a patient on a daily basis. The factors which may be considered in determining the dosage include the patient's age, weight, height and body surface area and the composition of the intravenous solution. The patient's age, weight, height, and body surface area are factors which are related to the energy which a patient expends. In other words, those factors can be used to determine the minimum amount of energy which a patient requires, from which dosages can be determined.
At the present time, energy requirements are not normally determined because the determination requires: (1) the use of complex mathematical equations which are not well known or readily available to medical personnel; or (2) direct or indirect measurement requires expensive analytical apparatus, significant manpower, and possibly the transport of very ill patients.
Eli Lilly & Co., many years ago, made available a three-piece slide calculator for determining caloric requirements. The calculator was intended for use in computing diets for diabetics and was similar to the normal slide rule. In other words, the calculator had a body, a movable slide and a movable cursor. Use of the calculator took into account weight, height, and age in determining energy requirements.
There also exists at the present time a large number of two-piece slide calculators for making calculations of various types. These calculators include an envelope-like structure having front and back panels and a slide member movable between the panels. These slide calculators are normally made of cardboard and are very inexpensive to produce.
It is the object of this invention to provide a slide calculator for determining basal energy expenditure, body weight, body surface area and/or carbohydrate dosage which can be made readily available to medical personnel who need to make such calculations.
Another object of the invention is to provide a slide calculator which can be inexpensively produced and can be made available at little or no cost.
These and other objects of the invention will become apparent from the following description and appended claims.